Method for catalytic conversion of hydrocarbons



June 15, 1948. 1.. J. WEBER 2,443,337

METHOD FOR CATALYTIC CONVERSION OF HYDROCARBONS Filed Aug. 24, 194A MELEVATOR INVENTOR. Louis 3. Weber- Dav-1 @0 AHhs.

Patented June 15, 1948 METHOD FOR CATALYTIC CONVERSION HYDROCARBONS Louis Joe Weber, Borger, 'l'exl, assignor to Phillips Petroleum Company, a corporation of Dela.

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Application August 24, 1944, Serial No. 550,936

1 mm. (Cl. 196-52) This invention relates to a novel method of and apparatus for catalytically cracking and dehydrogenating hydrocarbon gases.

An object of this invention is to provide a novel means for preheating hydrocarbon gases in the presence of a catalyst to cause selective cracking or dehydrogenation reactions to take place.

A further object of this invention is to provide a continuous process of this nature in which the catalyst is regenerated without interrupting the hydrocarbon processing reaction.

Another object of this invention is to provide an improved form of apparatus or catalyst case for accomplishing the catalytic reaction and regeneration of the catalyst in a continuous manner and without interruption' of the reaction during regeneration of the catalyst.

A further object is to provide means for dehydrogenating hydrocarbons in which the moving mechanical parts are few and operate at relatively low temperatures.

Another object is to provide a continuous onstream" method of this type in which it is not necessary to provide for cyclic off-stream operation.

A further object of the invention is to eliminate the necessity of using time cycle valves and expensive control equipment such as would be required in the operation of catalyst cases which operate intermittently on and ofi stream.

An important object of this invention is to plenished, dusted, graded and sifted without interrupting normal operation thereof.

Other and more detailed objects of this invention will be apparent from the following disclosure when taken in connection with the attached drawing.

This invention resides substantially in the combination, construction, arrangement, relative location of parts, steps and series of steps, all as herein disclosed.

In the accompanying drawings, the single figure is a vertical, cross-sectional view through a catalyst case in accordance with this invention showing some parts diagrammatically and others in elevation and illustrating the method of this invention.

The catalyst case which may be made of any suitable material and insulated if required includes a housing comprising an upper chamber 1 and a lower chamber 2 in communication through the connection portion 41 of reduced cross-sectional area. A feed device similar to the feeding devices 4 and 6,or the equivalent thereutilize the heat of the reaction resulting from burning the impurities off of the catalyst bed in an eflicient manner and to provide a method of cooling the burning gas to a point where it may be compressed by ordinary means.

Another important object of the invention is to provide a novel method of this type in which alternately oxidizing and reducing atmospheres within the catalyst case are eliminated. An advantage of'this is that it eliminates metal dusting which is detrimental to the catalyst in certain types of catalytic dehydrogenation.

A further object is to provide a catalyst case construction operated in conjunction with but a single bucket elevator which may serve several catalyst chambers thus eliminating duplicate parts on several units.

A further object of the invention involves a catalyst case in which the catalyst is continuously in movement thereby preventing plugging, fusing and bridging and exposing all parts of the catalyst bed uniformly to gas flow.

Another advantage of the catalyst case herein disclosed is that the catalyst may be changed, re-

of, may be included in the restricted passage 4! to control the feed of catalyst from the upper to the lower chamber. A catalyst inlet conduit 3 provided with any suitable form of feeding device 4 supplies the catalyst at a controlled rate into the upper end of the chamber l. After passing through the lower chamber, the catalyst is discharged through a conduit 5 at a controlled rate by means of a feeding device 6 into the bottom of an elevator 1. This elevator may be of any suitable construction, for example, a bucket conveyor adapted to carry the catalyst upwardly for return into the supply conduit 3. Any necessary fresh or make-up catalyst may be added through the pressure lock door ll.

Mounted within the chamber 2 is a manifold 8 to which are connected a number of finned tubes l0 which extend upwardly as shown into communication with the upper chamber I at the bottom thereof. The finned tubes l0 are arranged in a circular path about the chambers so as to discharge into the upper chambers at various points around the periphery thereof. At 9 is the supply pipe connection for the manifold 8 through which the hot regeneration gases are introduced, as will be explained later. At 13 is a supply pipe connection for introducing the gaseous hydrocarbon feed into the catalyst case. This connection discharges behind an annular screen l4 forming a distributing device for more or less uniformly distributing the gases about the base of the catalyst bed in the region IS. A pipe [5 connects to the top of chamber 2 by means of which the converted or reacted hydrocarbons are withdrawn from the catalyst case. Attached to the top of chamber I is a discharge pipe I6 controlled by a back pressure valve I1 through which connection the regenerating gas is withdrawn from the catalyst case.

Reference character I2 is applied to that portion of the catalyst bed into which heat is introduced by means of the finned tubes III. The portion I9 of the catalyst bed is a region of initial preheating of the catalyst and the region of cooling of the hot regeneration gases to a point suitable for discharge through the connection It for recompression and reuse.

While the above description will indicate the method of operation of this apparatus, the fol- 4 it is desirable that the hydrocarbon fed into the lower chamber Mac at a sufficiently high pressure so as to maintain the pressure in the lower chamher 2 slightly higher than the pressure in the upper chamber I. This prevents dilution of the feed stock by the regenerating'gases. The temperature of the carbon coveredcatalyst I8 leaving the lower end of chamber 2 is utilized to preheat the hydrocarbon feed before it reaches the lowing additional explanation will be helpful in understanding the full nature of the invention.

The catalyst particles, preferably in theform of pellets, are continuously removed from the bottom of chamber 2 through the conduit 5 for delivery by the conveyor 1 to the inlet feeder 4. The catalyst from the upper chamber I moves downwardly into the lower chamber 2, through the connection 41 and the rate of movement imparted to the catalyst by means of this apparatus in conjunction with the action of gravity, as controlled by the feeder 6, may set at any desired value. it is to be noted that the catalyst is continuously in motion. The hydrocarbon gaseous charge to be reacted is delivered by the connection I3 at the bottom of bed portion i8 well distributed throughout by means of the perforated distributor is. In the zone it this hydrocarbon charge, which is preferably preheated before delivery thereinto, is further preheated until it reaches a reaction temperature in that portion of the catalyst bed in about the region of the manifold ring 8. The reaction continues and is completed in the catalyst bed portion I2 and the hydrocarbon-discharged from the reaction chamber 2 by means of the connection I5 for such further processing as is required depending upon the nature of the feed and the products desired. While the reaction is taking place, a deposit of carbon and the like is formed on the catalyst in the reaction zone I2 and heat is removed from the catalyst bed.

Hot regenerating gases of any suitable and well known kind are introduced into the manifold 8 through the connection 9 and flow upwardly from the manifold through the finned tubes I0. Part of the heat of the reaction is supplied to the reaction none by conduction through the walls of the manifold 8 and the fins of the tubes I0. When the regenerating gases are discharged into the catalyst bed portion they are still at a high enough temperature to burn off the carbon deposit from the unregenerated catalyst which has been delivered into the upper end of chamber I and is progressing slowly downwardly throughthat chamber. By the time the catalyst has reached the discharge outlets of pipes III the carbon has been burned off and the catalyst is regenerated. During this purification step a large amount of heatis liberated raising the temperature of the regenerating gases and the catalyst. As the regenerating gases move upwardly through the preheating portion I9 of the catalyst bed and chamber I they give up heat thereto so that by the time they are discharged through the connection It they have been sufliciently cooled so that they can be recompressed and reused without employing special high temperature blowers or compressors. The back pressure valve I'I maintains a desired pressure in the upper chamber I and reaction zone. This preheating lowers the temperature of the catalyst to such a point that it can be easily handled by the feeder 6 and the conveyor-I even though they are constructed of low temperature materials.

In the dehydrogenating of butane to produce butene and butadiene few metallic materials have been found that will not dust of! and plug the catalyst when the catalyst chambers are alternately exposed to reducing hydrocarbon vapors.

and oxidizing regeneration gases. Since the upper chamber in the apparatus of this invention is always filled with an oxidizing atmosphere and the lower chamber with a reducing atmosphere, it is apparent that the effect of metal dusting will be greatly reduced. In some cases it may be necessary to line the lower chamber 2 with some corrosion resisting lining in which case a thin chromium alloy lining such as 27 chrome backed with a carbon steel plate can be used. Likewise many other variations in this respect may be employed.

By providing suitable screens and emptying and filling doors II in the elevator casing, the catalyst may be changed while the system is in operation, all as will be apparent to those skilled in the art.

The system comprising the catalyst case i and the elevator l with the supply and return connections 3 and 5 respectively comprises a sealed system which operates under the same pressure throughout. For this reason the supply of fresh catalyst to the system is made through a pressure lock diagrammatically illustrated at II, or any other suitable well known arrangement by means of which fresh material may be introduced into the system without loss of pressure in the system.

It is also within the scope of this invention to mix with the catalyst material some inert heat carrying material for the purpose of keeping the reaction as nearly as possible an isothermal reaction.

From the above description it will be apparent to those skilled in the ant that the subject matter of this invention both as to apparatus and method is capable of considerable variation by modifications and applications within the knowledge of those skilled in the art and I do not, therefore, desire to be strictly limited to the disclosure as givenherein for purposes of illustra tion. For example, it is obvious that the method herein disclosed is not limited to the use of any particular catalyst chemical nor is it limited to any particular reaction other than that it be-a catalytic reaction carried on in the gaseous phase.

What is claimed is:

A'continuous method for the catalytic conversion of hydrocarbons at elevated temperatures stantially filled with said contiguous mass of pellets and permitting relatively unrestricted flow of pellets therethrough; continuously contacting that portion of said contiguous mass of pellets flowing through said hydrocarbon preheating zone with a countercurrent stream of hydrocarbon gases introduced to said zone at a temperature substantially below conversion'temperature whereby said gases are raised substantially to conversion temperature and said pellets are substantially cooled; continuously contacting that portion of said contiguous mass of pellets flowing through said conversion zone with said countercurrent stream of hydrocarbon gases lust heated to reaction temperature and simultaneously continuously passing an oxygen-containing gas at a temperature substantially above conversion temperature through said conversion zone in indirect heat relation to both pellets and gases whereby said hydrocarbon gases are substantially converted to desired products at a substantially uniform temperature and said catalyst pellets become at least partially spent by deposition of carbonaceous materials thereon; continuously contacting that portion of said contiguous mass 5 of pellets flowing through said catalyst heating zone with a countercurrent stream of said oxygen-containing gas just passed through said conversion zone, whereby said carbonaceous materials are substantially removed from said pellets by combustion and said pellets are heated to a tem- 6. perature substantially above conversion temperature; continuously contacting that portion of said contiguous mass of pellets flowing through said catalyst preheating zone with a countercurrent 5 stream of emuent gases from said catalyst heating zone whereby said pellets are heated substantially and said gases are cooled substantially; continuously removing pellets from said hydrocarbon preheating zone; continuously introducing pellets to 10 said catalyst preheating zone; and continuously recovering the emuents from said conversion zone.

LOUIS JOE WEBER.

1 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 20 Number Name Date 2,264,438 Gaylor Dec. 2, 1941 2,290,580 Degnen et al. July 21, 1942 2,290,845 Voorhees Jul 21, 1942 2,303,717 Arveson Dec. 1, 1942 2,312,006 Thiele Feb. 23, 1943 2,320,318 Simpson et al May 25, 1943 2,348,009 Johnson et al. May 2, 1944 2,363,874 Krebs Nov. 28, 1944 2,374,151 Wolk et al. Apr. 17, 1945 30 2,387,378 Woik Oct. 23, 1945 2,389,636 Ramseyer Nov. 27, 1945 

